Huh. Just…huh.
SoCal shoots…and scores! 
Nightcrawlers, would be what they’d be after here, in the Heartland. Gawd knows whut they might be finding to eat in the grass growin’ in the Devil’s Playground. [snerk]
Well, they certainly don’t sound like hawks. Night-Herons could be a possibility, though the behavior would be unusual. But without a more detailed description it’s a bit hard to say for sure.
Where are you running? I know that there is a large population of Canadian Geese at Vasona Park, and along the Los Gatos Creek Trail near the perk ponds. I would suspect that you’d see them at Central Park in Santa Clara, or or any park with a large body of water. The only terrestrial birds of prey that I recall seeing around here were burrowing owls at the northern outskirts of Santa Clara County before the rise of Silicon Valley. The last time I saw them was when Mission College first opened up. They’re probably all gone now.